There are also a couple of videos on youtube that some may find to be helpful.
Backcombing Synthetic Hair for Dreads:
http://www.youtube.com/watch?v=Wd43lmdbnv8
Sealing a Swirled dread:
http://www.youtube.com/watch?v=UyPYwa64VHw
Yarn braid extentions:
http://www.youtube.com/watch?v=1Ys5H7G-iUo
More yarn type falls:
http://www.youtube.com/watch?v=RtsoiBbGreE
Didnt find any videos for roving. I have a friend who does it and she molds the yarn by spinning it between the palms of her hands while using soap and hot water to get the desired shape. She buys her yarn online. I may try it sometime when I've got the patience.
Falls work best for those who have jobs that require you to look conformed to the environment you happen to be in. That's my take on it anyways.